What Is Limiting Pyrite Solar Cell Performance?

摘要： Iron pyrite (FeS2), an earth-abundant transition metal di-chalcogenide (TMD), has exotic electronic and optical properties suitable for solar cell applications. For example, it has an indirect band gap at (cid:1)0.95 eV and a direct band gap at 1.05–1.10 eV that is comparable to Si (1.1 eV), while absorption coef?cient of FeS2 is almost two orders of magnitudes higher than that of Si. Like Si, FeS2 solar cells also could have almost same theoretical energy conversion ef?ciency up to Shockley-Queisser limit. Additionally, the high absorption coef?cient of FeS2 offers the opportunities to fabricate a very thin absorber layer of thickness < 20 nm, which so far does not seem possible with other thin-?lm solar cell materials. It infers a sharp reduction of the production cost (￠/W) of electricity due to reduction of material cost. Consequently, FeS2 has gained interest as a potential non-toxic super absorber material in lieu of widely used but toxic and rare element containing CdTe and Cu(In, Ga)Se2 for thin-?lm solar cells.